DNA & GENETICS STUDY GUIDE

DNA

A strand of molecules called nucleotides. Strands are packed by special proteins called histones; all living things have DNA.

Monomer

A molecule that can be bonded to other identical molecules to form a polymer

i.e. nucleic acids are composed of monomers, called nucleotides, which are combined to form large strands

DNA

A strand of molecules called nucleotides. Strands are packed by special proteins called histones; all living things have DNA.

Monomer

A molecule that can be bonded to other identical molecules to form a polymer

i.e. nucleic acids are composed of monomers, called nucleotides, which are combined to form large strands

Polymer

A long strand of nucleotides bonded together

Deoxyribose

Pentase sugar important in the formation of DNA

Phosphate group

Gives the DNA molecule a negative charge and provides structural support

Nitrogen base

What makes the nucleotides different; adenine, thymine , cytosine guanine

Nucleic Acid

Each strand of DNA is made of nucleotides bonded into a long chain

-nucleic acid is a long strand made of nucleotides

-nucleotides are smaller molecules that make the strand

Double helix

Two strands linked together and twisted into a helix shape that is made of a series of nucleotides, which is what makes DNA

Anti parallel

Back phone running in opposite directions, and nucleotides flipped

-allows base pairs to complement one another and form the hydrogen bonds

Complementary base pair

States that DNA base pairs are always

Adenine & thymine

Cytosine and Guanine

Chromosome

A thread light structure of nucleic acids and proteins found in the nucleus of most living cells, caring genetic information in the form of genes

Chromatin

The material of which the chromosome of organisms other than bacteria are composed; consist of protein, RNA and DNA

Chromatid

One of the two identical, halves of a chromosome that has been replicated in preparation for cell division

Topoisomerase

Unwinds DNA, makes it easier to access easier

Helicase

“Unzips” the helix by breaking hydrogen bonds at a replication fork

Primase

RNA primer for RNA primer which acts as a signal to indicate where to start replication

DNA Polymerase

And complementary bases to each strand

Ligase

bonds Okazaki fragments of the lagging strand

• has the power to create chemical bonds

Leading strand

As synthesized continuously, no gaps

Lagging Strand

Synthesize discontinuously creating pieces

Okazaki Fragments

Chunks of DNA made by DNA polymerase

Continuous replication

Proceed immediately only along the leading strand

Discontinuous replication

Replication of the lagging strand in the direction opposite of unwinding; DNA must be synthesized in short stretches

Semi-conservative

Two strands of nucleotides separate that form the template for new nucleotides to bind to create two identical, daughters strands

Promoter sequence

A short string of faces in the DNA right before the genes first codon

Gene

A segment of DNA that codes for a specific protein in cells

mRNA

Serves as messengers between DNA and the rest of the cell

tRNA

transfers, an amino acid to the ribosome by the coded in mRNA

Uracil

Occurs in RNA is found a positions complementary to adenine

Ribosome

A cellular machine responsible for making proteins

Codon

Three mrna nucleotides each codes a specific amino acid

Anti-codon

TRNA contains matching and take anti-codons

Amino acid

Protein made of single units

Gene expression

The process of by which the information encoded in a gene is turned into a function

Gene level mutation

DNA at the molecule level by changing the normal sequence of nucleotide base parts; occurs during the process of DNA replication

Chromosomal mutation

affects entire portions of the chromosome entire genes or sets of genes are altered, rather than only single nucleotides of DNA

Substitution

When a tie is replaced with a different nucleotide in the DNA sequence (A letter changes)

Insertion

The addition of nucleotides to the sequence

Deletion

The removal of nucleotides from the sequence

Silent

No change in amino acid

Missense

Changes an amino acid to another acid

Nonsense

Changes in amino acid to a stop codon resulting in premature termination of translation